Light emitting device and light emitting device package thereof

ABSTRACT

A light emitting device includes a light emitting structure including a second conduction type semiconductor layer, an active layer, and a first conduction type semiconductor layer, a second electrode layer arranged under the light emitting structure, a first electrode layer having at least portion extending to contact the first conduction type semiconductor layer passing the second conduction type semiconductor layer and the active layer, and an insulating layer arranged between the second electrode layer and the first electrode layer, between the second conduction type semiconductor layer and the first electrode layer, and between the active layer and the first electrode layer, wherein said at least one portion of the first electrode layer contacting the first conduction type semiconductor layer has a roughness.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is a Division of co-pending U.S. patentapplication Ser. No. 13/102,478 filed May 6, 2011, which claims priorityunder 35 U.S.C. 119(a) of Korean Patent Application No. 10-2010-0099215filed on Oct. 12, 2010 and 10-2010-0132553 filed on Dec. 22, 2010, whichis hereby incorporated by reference in its entirety.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

The present invention relates to a light emitting device, a lightemitting device package thereof, a lighting device and a display device.

Discussion of the Related Art

A light emitting diode LED is a kind of semiconductor device forconverting electricity into an infrared ray or a light by utilizing acharacteristic of a compound semiconductor to transmit/receive a signal,or using as a light source.

Owing to physical and chemical characteristics, group III-V nitridesemiconductors are spot lighted as essential materials of a lightemitting device, such as the light emitting diode LED or a laser diodeLD.

Since the light emitting diode is very environment friendly having nosubstances which harm an environment, such as mercury Hg used in thepresent lighting devices, such as incandescent lamps and fluorescentlamps, and has a long lifetime and low power consumption, the lightemitting diode is replacing the present light sources.

SUMMARY OF THE DISCLOSURE

An object of the present invention is to provide a light emittingdevice, and a light emitting device package thereof.

Additional advantages, objects, and features of the disclosure will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, alight emitting device includes a light emitting structure including asecond conduction type semiconductor layer, an active layer, and a firstconduction type semiconductor layer, a second electrode layer arrangedunder the light emitting structure, a first electrode layer having atleast portion extending to contact the first conduction typesemiconductor layer passing the second conduction type semiconductorlayer and the active layer, and an insulating layer arranged between thesecond electrode layer and the first electrode layer, between the secondconduction type semiconductor layer and the first electrode layer, andbetween the active layer and the first electrode layer, wherein said atleast one portion of the first electrode layer contacting the firstconduction type semiconductor layer has a roughness.

Since the contact electrode has the roughness at the top side, thecontact electrode has an increased contact area with the firstconduction type semiconductor layer. And, as the resistance of the firstelectrode layer decreases more and more when the contact area betweenthe contact electrode and the first conduction type semiconductor layerincreases, an operation voltage of the light emitting device can beimproved. For an example, by dropping the operation voltage of the lightemitting device, optical output efficiency of the light emitting devicecan be improved. Moreover, as adhesion between the first electrode layerand the first conduction type semiconductor layer increases the more asthe contact area between the first electrode layer and the firstconduction type semiconductor layer increases the more, so reliabilityof the light emitting device can be improved.

The light emitting device can further include a support substrate underthe first electrode layer, wherein the first electrode layer can includeat least one contact electrode in contact with the first conduction typesemiconductor layer passing through the second electrode layer, thesecond conduction type semiconductor layer, and the active layer, andthe at least one contact electrode has a top side with the roughness.The first electrode layer can include a lower electrode layer arrangedbetween the support substrate and the second electrode layer, and the atleast one contact electrode which is a branch from the lower electrodelayer in contact with the first conduction type semiconductor layer.

The contact electrode may have a width of 5 μm˜200 μm, a height from atop side of the active layer to a top side of the contact electrode maybe 0.4 μm˜10 μm, and the roughness may have a width of 0.02 μm˜100 μm,and a height of 0.2 μm˜10 μm.

The width of the contact electrode may be higher than 5 μm since it isthe minimum size for the current to flow through the contact electrodeefficiently. Meanwhile, the width of the contact electrode may be lowerthan 200 μm so that a plurality of contact electrodes may be formed inlight of common chip size.

The height from a top side of the active layer to a top side of thecontact electrode may be 0.4 μm˜10 μm. The lower limit of the height maybe set as 0.4 μm since it is a minimum value to protect electrical shortwith active layer. The upper limit of the height may be set as 10 μm inlight of the height of the first conduction type semiconductor layer(GaN) which is usually in the range of 4˜6 μm.

The roughness may have a width of 0.02 μm˜100 μm. The width of theroughness may be higher than 0.02 μm since 0.02 μm is the minimum valuethat can be practically manufactured. The maximum value of the width ofthe roughness may be set as 100 μm so that a plurality of roughness canbe formed.

The roughness may have a height of 0.2 μm˜10 μm. The minimum value ofthe height of the roughness may be 0.2 μm since the roughness which hassmaller height is difficult to manufacture. The upper limit of theheight may be set as 10 μm in light of the height of the firstconduction type semiconductor layer (GaN) which is usually in the rangeof 4˜6 μm.

The insulating layer can be arranged between the lower electrode layerand the second electrode layer, between a side of the contact electrodeand the second electrode layer, between the side of the contactelectrode and the second conduction type semiconductor layer, andbetween the side of the contact electrode and the active layer.

The roughness can have a vertical cross-section presenting a stepwisestructure or a tiered structure.

The first electrode layer can be arranged on the second electrode layer,and can include a contact portion in contact with the first conductiontype semiconductor layer overlapped with the light emitting structure ina vertical direction, and an exposed portion not overlapped with thelight emitting structure in the vertical direction and exposed from thelight emitting structure, wherein the vertical direction can be adirection facing from the second electrode layer toward the firstconduction type semiconductor layer, and a top side of the contactportion can have the roughness.

The first electrode layer can have at least one further portionoverlapped by the light emitting structure having a top side with aroughness in contact with the first conduction type semiconductor layer.

The first electrode layer can include a contact portion in contact withthe first conduction type semiconductor layer, and an exposed portionopened from the first conduction type semiconductor layer, wherein thecontact portion can have a roughness.

The light emitting structure can be divided into a plurality of cellregions spaced from one another on the second electrode layer bypredetermined distances, and the first electrode layer can include acontact portion in contact with the first conduction type semiconductorlayer passed through the second conduction type semiconductor layer andthe active layer of each of the plurality of cell regions, and anexposed portion exposed from the first conduction type semiconductorlayer, wherein the contact portion can have the roughness.

The first electrode layer can include at least one of an ohmic layer, areflective layer, and a bonding layer.

The at least one contact electrode can have a top side higher than a topside of the active layer, and lower than a top side of the firstconduction type semiconductor layer.

The second electrode layer can have one side region opened from thelight emitting structure, and can further include a second electrode padarranged on the one opened side region.

The first electrode layer can have one side opened from the lightemitting structure, and can further include a first electrode padarranged on the one opened side of the first electrode layer.

The insulating layer surrounds the at least one contact electrode,wherein a portion of the insulating layer which surrounds the side ofthe at least one contact electrode can have a roughness in contact withthe first conduction type semiconductor layer, and the roughness canhave a random irregular shape. The light emitting device can furtherinclude a protective layer arranged at a sidewall of the light emittingstructure.

In another aspect of the present invention, a light emitting devicepackage includes a package body, a light emitting device in accordancewith the present invention on the package body, a first electrode layerand a second electrode layer provided on the package body connected tothe light emitting device, and a resin layer which surrounds the lightemitting device.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the disclosure andtogether with the description serve to explain the principle of thedisclosure. In the drawings:

FIG. 1 illustrates a section of a light emitting device in accordancewith a preferred embodiment of the present invention.

FIG. 2 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 3 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 4 illustrates an enlarged section of the contact electrode in FIG.1.

FIG. 5 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 6 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 7 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 8 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 9 illustrates a plan view of the light emitting device in FIG. 8.

FIG. 10 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 11 illustrates a plan view of the light emitting device in FIG. 10.

FIG. 12 illustrates a plan view of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIGS. 13˜17 illustrate sections showing the steps of a method forfabricating a light emitting device in accordance with a preferredembodiment of the present invention.

FIGS. 18 and 19 illustrate sections showing the steps of a method forfabricating a light emitting device in accordance with another preferredembodiment of the present invention.

FIGS. 20 and 25 illustrate sections showing the steps of a method forfabricating a light emitting device in accordance with another preferredembodiment of the present invention.

FIG. 26 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 27 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 28 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 29 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention.

FIG. 30 illustrates a section of a light emitting device package inaccordance with a preferred embodiment of the present invention.

FIG. 31 illustrates an exploded perspective view of a lighting devicehaving a light emitting device in accordance with another preferredembodiment of the present invention applied thereto.

FIG. 32A illustrates an exploded perspective view of a display devicehaving a light emitting device package in accordance with a preferredembodiment of the present invention applied thereto, and FIG. 32Billustrates a section of a light source portion of the display device inFIG. 32A.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Reference will now be made in detail to the specific embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. In description of embodiments that a layer (a film), a region,a pattern, or a structure is formed “on” or “under” a substrate, a layer(a film), a region, a pad, or pattern, the “on”, or “under” implies thatthe layer (the film), the region, the pattern, or the structure isformed “on” or “under” the substrate, the layer (the film), the region,the pad, or the pattern directly or indirectly with other substrate,layer (film), region, pad, or pattern, disposed therebetween. And, in acase of expression of “on or under”, the expression can mean, not onlyan upper side, but also an underside of an element.

A size shown in a drawing is exaggerated, omitted or shown schematicallyfor convenience or clarity of description. And, a size of an element isnot shown to scale, perfectly. Wherever possible, the same referencenumbers will be used throughout the drawings to refer to the same orlike parts. A light emitting device, a method for fabricating the same,and a light emitting device package thereof in accordance with apreferred embodiment of the present invention will be described withreference to the attached drawings.

FIG. 1 illustrates a section of a light emitting device 100 inaccordance with a preferred embodiment of the present invention.Referring to FIG. 1, the light emitting device 100 includes a lightemitting structure 130 having a second conduction type semiconductorlayer 132, an active layer 134, and a first conduction typesemiconductor layer 136, a second electrode layer 120 arranged under thelight emitting structure 130 in contact with the second conduction typesemiconductor layer 132, a first electrode layer 115 in contact with thefirst conduction type semiconductor layer 136 passed through the secondelectrode layer 120, the second conduction type semiconductor layer 132and the active layer 134, an insulating layer 140 arranged between thesecond electrode layer 120 and the first electrode layer 115, betweenthe second conduction type semiconductor layer 132 and the firstelectrode layer 115, and between the active layer 134 and the firstelectrode layer 115, a protective layer 170 arranged at a side of thelight emitting structure 130, and a second pad 190 arranged on thesecond electrode layer 120 exposed from the light emitting structure130, wherein a portion of the first electrode layer 115 in contact withthe first conduction type semiconductor layer 136 has an uneven portion118, e.g. roughness. The light emitting device 100 can include a supportsubstrate 110 on an underside of the first electrode layer 115.

The light emitting device 100 includes an LED having a plurality ofcompound semiconductor layers, for an example, compound semiconductorlayers of group 3˜5 elements, wherein the LED can be a color LED whichemits a blue color, a green color, or a red color, or an UV LED. Thelight from the LED can be produced by using different semiconductor, andis not limited to above.

The support substrate 110 can be a conductive substrate or an insulatingsubstrate, and supports the light emitting structure 130. For anexample, the support substrate 110 can be a base substrate having apredetermined thickness of copper Cu, gold Au, nickel Ni, molybdenum Mo,or copper-tungsten Cu-W, and can include at least one of a carrierwafer, for an example, Si, Ge, GaAs, ZnO, and SiC, and a conductivesheet.

The first electrode layer 115 is arranged on the support substrate 110.The first electrode layer 115 can include at least one of an ohmiclayer, a reflective layer, a bonding layer. The first electrode layer115 can be in ohmic contact with the first conduction type semiconductorlayer 136 or the support substrate 110 by using a reflective metal or aconductive oxide.

The first electrode layer 115 can include at least one of ITO (indiumtin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tinoxide), GZO (gallium zinc oxide), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au, andNi/IrOx/Au/ITO. However, materials of the first electrode layer 115 arenot limited to above materials.

Or, the first electrode layer 115 can be formed of Ag, Ni, Al, Rh, Pd,Ir, Ru, Mg, Zn, Pt, Au, Hf and a selective combination of abovematerials. Or, the first electrode layer 115 can be single or multiplelayers of a reflective electrode material. If the first electrode layer115 has an ohmic characteristic, no additional ohmic layer can berequired.

Moreover, the first electrode layer 115 can include an adhesive layerwhich improves adhesion to the support substrate 110. In this instance,the adhesive layer can include a barrier metal or a bonding metal. Foran example, the adhesive layer can include at least one of Ti, Au, Sn,Ni, Cr, Ga, In, Bi, Cu, Ag or Ta.

The second electrode layer 120 is arranged on the first electrode layer115, and the insulating layer 140 is arranged between the secondelectrode layer 120 and the first electrode layer 115 for insulating thefirst electrode layer 115 from the second electrode layer 120.

Though the second electrode layer 120 can be a stacked structure ofohmic layer/reflective layer/bonding layer, or a stacked structure ofohmic layer/reflective layer, or a stacked structure of reflective layer(ohmic layer)/bonding layer, the structure of the second electrode layer120 is not limited to above. For an example, the second electrode layer120 can have a structure in which the reflective layer 122 and the ohmiclayer 124 are stacked on the insulating layer 140 in succession.

The reflective layer 122 is arranged between the ohmic layer 124 and theinsulating layer 140, and can be formed of a material havingreflectivity greater than 50%. For an example, the reflective layer 122can be formed of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf or analloy of a selective combination of above materials, or multiple layersof above materials and a light transmissive conductive material of IZO,IZTO, IAZO, IGZO, IGTO, AZO, and ATO. For an example, the reflectivelayer 122 can have a stacked structure of IZO/Ni, AZO/Ag, IZO/Ag/Ni, orAZO/Ag/Ni. Or, if the reflective layer 122 is formed of a material whichis in ohmic contact with the light emitting structure (For an example,second conduction type semiconductor layer 132), no additional ohmiclayer 124 may be formed. However, the present invention is not limitedto this.

The ohmic layer 124 is in ohmic contact with an underside of the lightemitting structure 130 (For an example, the second conduction typesemiconductor layer 132) and can be a layer or a plurality of patterns.For an example, the ohmic layer 124 can be single or multiple layers ofat least one selected from ITO (indium tin oxide), IZO (indium zincoxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide),IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO(aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zincoxide), IrOx, RuOx, RuOx/ITO, Ni, Ag, Ni/IrOx/Au, and Ni/IrOx/Au/ITO.The ohmic layer 124 is formed for making smooth injection of a carrierinto the second conduction type semiconductor layer 132, and thereforeis not essential.

The light emitting structure 130 is arranged on the second electrodelayer 120. The light emitting structure 130 can be in a mode in whichthe second conduction type semiconductor layer 132, the active layer134, and the first conduction type semiconductor layer 136 are stackedin succession.

The second conduction type semiconductor layer 132 is arranged on theohmic layer 124 to be in ohmic contact with the ohmic layer 124. Thesecond conduction type semiconductor layer 132 can be a compoundsemiconductor of group 3˜5 elements having a second conduction typedopant doped thereto.

The second conduction type semiconductor layer 132 can be formed of asemiconductor material having composition of InxAlyGa1−x−yN (0≦x≦1,0≦y≦1, 0≦x+y≦1), for an example, one selected from GaN, AlN, AlGaN,InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and canhave a p type dopant, such as Mg, Zn, Ca, Sr, Ba doped thereto. Thesecond conduction type semiconductor layer 132 can have single ormultiple layers, but the present invention does not limit this.

The active layer 134 is arranged on the second conduction typesemiconductor layer 132 of a compound semiconductor of group 3˜5elements. The active layer 134 can be formed of a semiconductor materialhaving composition of InxAlyGa1−x−yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1), and caninclude any one of single Quantum Well structure, a Multi Quantum Wellstructure, a Quantum dot structure or a Quantum wire structure.

The active layer 134 can be constructed of a well layer/a barrier layerof a compound semiconductor of group 3˜5 elements, for an example, InGaNwell layer/GaN barrier layer or InGaN well layer/AlGaN barrier layer.There can be a conductive clad layer of an AlGaN group semiconductorarranged between the active layer 134 and the first conduction typesemiconductor layer 136 or between the active layer 134 and the secondconduction type semiconductor layer 132.

The first conduction type semiconductor layer 136 is arranged on theactive layer 134 and can be a compound semiconductor of group 3˜5elements having a first conduction type dopant doped thereto. The firstconduction type semiconductor layer can be formed a semiconductormaterial having composition of InxAlyGa1−x−yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1),for an example, a semiconductor material selected from GaN, AlN, AlGaN,InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and canhave an n type dopant, such as Si, Ge, Sn, Se, Te doped thereto. Thefirst conduction type semiconductor layer 136 can be constructed ofsingle or multiple layers. However, the present invention does not limiton this. The first conduction type semiconductor layer 136 can have atop side with a roughness 160 or a pattern formed thereon for opticalextraction efficiency.

The first conduction type semiconductor layer 136 can be arranged on atop of a chip, the active layer 134 can be arranged on an underside ofthe first conduction type semiconductor layer 136, the second electrodelayer 120 can be arranged on an underside of the second conduction typesemiconductor layer 132, the insulating layer 140 can be arranged on anunderside of the second electrode layer 120, the first electrode layer115 can be arranged on an underside of the insulating layer 140, and thesupport substrate 110 can be arranged on an underside of the firstelectrode layer 115.

The first electrode layer 115 is in contact with the first conductiontype semiconductor layer 136 passed through the second electrode layer120, the second conduction type semiconductor layer 132, and the activelayer 134 in a vertical direction, and an insulating layer 140 isarranged between a passed through portion of the second electrode layer120 and the first electrode layer 115, between a passed through portionof the second conduction type semiconductor layer 132 and the firstelectrode layer 115, and between a passed through portion of the activelayer 134 and the first electrode layer 115. A vertical directionmentioned hereafter is a direction facing from the first electrode layer115 toward the first conduction type semiconductor layer 136.

For an example, the first electrode layer 115 has at least one contactelectrode 115-2 which is a branch in the vertical direction in contactwith the first conduction type semiconductor layer 136 passed throughthe second electrode layer 120, the second conduction type semiconductorlayer 132, and the active layer 134.

The first electrode layer 115 can include a lower electrode layer 115-1and at least one contact electrode 115-2. The lower electrode layer115-1 is in contact with the support substrate 110 and is parallelthereto. The at least one contact electrode 115-2 is in electric contactwith the first conduction type semiconductor layer 136 which is a branchfrom the lower electrode layer 115-1 in the vertical direction passedtrough the second electrode layer 120, the second conduction typesemiconductor layer 132, and the active layer 134. In this instance, theat least one contact electrode 115-2 has a top side positioned higherthan the active layer 134 and lower than a top side of the firstconduction type semiconductor layer 136. That is, a portion of the topside of the contact electrode 115-2 can be arranged in the firstconduction type semiconductor layer 136.

The contact electrode 115-2 has a roughness 118 at the top side. In thisinstance, the roughness 118 can have a regular or an irregular pattern.For an example, the roughness 118 can be a random roughness at a portionin contact with the first conduction type semiconductor layer 136. Thetop side of the contact electrode 115-2 having the roughness 118 is incontact with the first conduction type semiconductor layer 136. In thisinstance, the top side of the contact electrode 115-2 having theroughness 118 can be in ohmic contact with the first conduction typesemiconductor layer 136.

Since the contact electrode 115-2 has the roughness 118 at the top side,the contact electrode 115-2 has an increased contact area with the firstconduction type semiconductor layer 136. And, as resistance of the firstelectrode layer 115 decreases the more as the contact area between thecontact electrode 115-2 and the first conduction type semiconductorlayer 136 increases the more, an operation voltage of the light emittingdevice 100 can be improved. For an example, by dropping the operationvoltage of the light emitting device, optical output efficiency of thelight emitting device can be improved. And, as adhesion between thefirst electrode layer 115 and the first conduction type semiconductorlayer 136 increases the more as the contact area between the firstelectrode layer 115 and the first conduction type semiconductor layer136 increases the more, reliability of the light emitting device 100 canbe improved.

FIG. 4 illustrates an enlarged section of the contact electrode inFIG. 1. Referring to FIG. 4, the contact electrode 115-2 can have awidth D1 of 5 μm˜200 μm, preferably 60 μm. A height D2 of a portion ofthe top side of the contact electrode 115-2 arranged in the firstconduction type semiconductor layer 136, i.e., a height D2 from a topside of the active layer 134 to a top side of the contact electrode115-2 can be 0.4 μm˜10 μm, preferably, 0.8 μm.

A horizontal direction cross section of the roughness 118 formed at thetop side of the contact electrode 115-2 can have various shapes. For anexample, the section can be circular or polygonal including square. Inthis instance the horizontal direction can be a direction parallel tothe support substrate 310.

A width D3 of the roughness 118 formed at the top of the contactelectrode 115-2 can be 0.02 μm˜100 μm, preferably 40 μm. For an example,the width D3 can be a diameter of a section if the section is circular,and a length of one side if polygonal. And, a height D4 of the roughness118 formed at the top side of the contact electrode 115-2 can be 0.2μm˜10 μm, preferably 1 μm˜2 μm.

The contact electrode 115-2 can be branches from the lower electrodelayer 115-1 such that a plurality of the contact electrodes 115-2 arearranged spaced from one another. If the contact electrode 115-2 isplural, smooth current supply to the first conduction type semiconductorlayer 136 can be made.

Though the contact electrode 115-2 can have at least one of patternsselected from a radial pattern, a cross pattern, a line pattern, a curvepattern, a loop pattern, a hook pattern, and a ring pattern, the patternof the contact electrode 115-2 is not limited to this.

The insulating layer 140 insulates the first electrode layer 115 fromother layers 120, 132, and 134. The insulating layer 140 is positionedbetween the first electrode layer 115 and the second electrode layer 120for insulating the first electrode layer 115 from the second electrodelayer 120, electrically. That is, the insulating layer 140 is arrangedbetween the lower electrode layer 115-1 and the reflective layer 122 forelectric insulation of the lower electrode layer 115-1 from thereflective layer 122.

And, a portion 141 of the insulating layer 140 is arranged in each ofspaces between a side of the contact electrode 115-2 and the secondelectrode layer 120, between a side of the contact electrode 115-2 andthe second conduction type semiconductor layer 132, and between a sideof the contact electrode 115 and the active layer 134 for electricinsulation of the contact electrode 115-2 from other layers 120, 132,and 134. And, the insulating layer 140 can be arranged between the sideof the contact electrode 115-2 and the first conduction typesemiconductor layer 136, too.

For an example, the portion 141 of the insulating layer 140 can bearranged to surround the sides of the contact electrode 115-2 except thetop side of the contact electrode 115-2 for blocking electric shortswith other layers 120, 132, and 134.

One side region of the second electrode layer 120, for an example, oneside region of the ohmic layer or/and the reflective layer 122, can beexposed from the light emitting structure 130, and the second electrodepad 190 is arranged on the one side region P1 of the second electrodelayer 120. In this instance, the one region of the second electrodelayer 120 can be the outermost peripheral region of the second electrodelayer 120.

The second electrode pad 190 can have an electrode shape. And, theprotective layer 170 can be arranged at a side of the light emittingstructure 130 adjacent to the one side region P1 of the second electrodelayer 120 exposed thus. For an example, the protective layer 170 can bearranged at a side of the second conduction type semiconductor layer 132adjacent to the one side region P1 of the second electrode layer 120exposed thus, a side of the active layer 134, and a portion of a side ofthe first conduction type semiconductor layer 136. The protective layer170 is arranged to cover at least the active layer 134, and, though theprotective layer 170 can be arranged on an edge region of the top sideof the first conduction type semiconductor layer 136 adjacent to theside of the light emitting structure 130, arrangement of the protectivelayer 170 is not limited to this. The protective layer 170 can preventthe electric short from taking place between the light emittingstructure 130 and the second electrode pad 190.

FIG. 2 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention. Partsidentical to the parts in the embodiment shown in FIG. 1 will be givenidentical reference numerals, and description of duplicated portionsthereof will be omitted.

Referring to FIG. 2, the light emitting device 200 includes a supportsubstrate 110, a first electrode layer 116, a second electrode layer120, a light emitting structure 130, an insulating layer 140-1, aprotective layer 170, a first electrode pad 210, and a second electrodepad 190.

The first electrode layer 116 has one side, for an example, one side ofa lower electrode layer 116-1, exposed to an outside from the lightemitting structure 130, and the first electrode pad 210 is arranged onthe one side region P2 of the first electrode layer 116 exposed thus.The first electrode pad 210 can be singular or plural spaced from oneanother. There is a contact electrode 116-2 which can be identical tothe contact electrode 115-2 in FIG. 2.

The second electrode layer 120 has one side, for an example, one side ofthe ohmic layer 124 or/and the reflective layer 122, exposed to anoutside from the light emitting structure 130, and the second electrodepad 190 is arranged on one side region P1 of the second electrode layer120 opened thus. In this instance, the one side region P1 of the secondelectrode layer 120 opened thus can be singular or plural, and can havea plurality of second electrode pads 190 provided thereto.

In this instance, while the one side exposed region P2 of the firstelectrode layer 116 is positioned adjacent to the one side of the lightemitting structure 130, the one side exposed region P1 of the secondelectrode layer 120 can be positioned adjacent to the other side of thelight emitting structure 130. However, the one side exposed region P2 ofthe first electrode layer 116 and the one side exposed region P1 of thesecond electrode layer 120 are not limited to this, but can be producedin different shapes.

There can be a protective layer 170-1 arranged around the light emittingstructure 130, to cover at least sides of the second conduction typesemiconductor layer 132 and the active layer 134. For an example, theprotective layer 170-1 can be arranged at a side of the secondconduction type semiconductor layer 132 adjacent to the one side regionP1 of the second electrode layer 120 exposed thus and the one sideregion P2 of the first electrode layer 116 exposed thus, a side of theactive layer 134, and a portion of one side of the first conduction typesemiconductor layer 136. And, though the protective layer 170-1 can bearranged at an edge region of a top side of the first conduction typesemiconductor layer 136 adjacent to the side of the light emittingstructure 130 too, the arrangement of the protective layer 170-1 is notlimited to this. The protective layer 170-1 prevents electric shortsfrom taking place between the first electrode pad 210 and the secondelectrode pad 190 and the light emitting structure 130 for preventinginter-layer shorts.

In the embodiment shown in FIG. 2, by arranging the first electrode pad210 and the second electrode pad 190 on an outer side of the chip, wirebonding to the electrode pads 190 and 210 can be made simple. Moreover,since the first electrode pad 210 is not arranged on the firstconduction type semiconductor layer 136, not reducing a size of thelight emitting region of the top side of the first conduction typesemiconductor layer 136, the optical extraction efficiency can beimproved. And, since the power of a first polarity and a second polaritycan be supplied through a lower side of the chip, a light emittingdevice having a new current path can be provided.

FIG. 3 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention. Partsidentical to the parts in the embodiment shown in FIG. 1 will be givenidentical reference numerals, and description of duplicated portionswill be omitted.

Referring to FIG. 3, the contact electrode 115 has a top side with astair structured roughness 119. A vertical direction section of theroughness 119 can have a two-tiered stair structure. In this instance,the vertical direction can be a direction facing from a top side of thecontact electrode 115 toward a top side of the roughness 119. Though theroughness 119 in FIG. 3 shows a roughness 119 having a two-tiered stairstructure from the top side of the contact electrode 115 to the top sideof the roughness 119, the structure of the roughness 119 is not limitedto this, but the roughness 119 can be more than two tiers.

Since the contact electrode 115-2 has the stair structured roughness 119at the top side, increasing a contact area with the first conductiontype semiconductor layer 136 dropping resistance of the first electrodelayer 115, an operation voltage of the light emitting device 200 isimproved, and reliability of the light emitting device 200 is improvedas adhesion between the first electrode layer 115 and the firstconduction type semiconductor layer 136 is increased.

FIG. 5 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention. As shown inFIG. 5, the light emitting device 300 includes a light emittingstructure 330 having a second conduction type semiconductor layer 332,an active layer 334, and a first conduction type semiconductor layer336, a second electrode layer 320 arranged under the light emittingstructure 330 in contact with the second conduction type semiconductorlayer 332, a first electrode layer 350 in contact with the firstconduction type semiconductor layer 336 passed through the secondconduction type semiconductor layer 332 and the active layer 334, and aninsulating layer 340 arranged between each of the second electrode layer320, between the second conduction type semiconductor layer 332, and theactive layer 134, and between the first electrode layer 115, wherein aportion of the first electrode layer 350 in contact with the firstconduction type semiconductor layer 336 has a roughness 375.

The second electrode layer 330 can be embodied as single layer ormultiple layers of at least one selected from ITO, IZO, IZTO, IAZO,IGZO, IGTO, AZO, ATO, GZO, IrOx, RuOx, RuOx/ITO, Ni, Ag, Ni/IrOx/Au, andNi/IrOx/Au/ITO.

And, the second electrode layer 320 can be formed of Ag, Ni, Al, Rh, Pd,Ir, Ru, Mg, Zn, Pt, Au, Hf and a selective combination of abovematerials for reflection. And, the second electrode layer 320 can beconstructed as multiple layers of light transmissive conductivematerial, such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO together withabove metals. For an example, the second electrode layer 320 can be astack of IZO/Ni, AZO/Ag, IZO/Ag/Ni, or AZO/Ag/Ni. The second electrodelayer 320 can be a bonded layer having a barrier metal and a bondingmetal. For an example, the second electrode layer 320 can include atleast one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag or Ta.

The light emitting structure 330 is arranged on a first region A of thesecond electrode layer 320, and includes the second conduction typesemiconductor layer 332, the active layer 334, and the first conductiontype semiconductor layer 336. The second conduction type semiconductorlayer 332, the active layer 334, and the first conduction typesemiconductor layer 336 are identical to ones described with referenceto FIG. 1.

There is a conductive layer 360 arranged on the first conduction typesemiconductor layer 336, and the conductive layer 360 is formed of alight transmissive material selected from oxides or nitrides, for anexample, ITO, IZO (indium zinc oxide), IZTO (indium zinc tin oxide),IAZO (indium aluminum zinc oxide), IGZO (indium gallium zinc oxide),IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO(antimony tin oxide), GZO (gallium zinc oxide).

The first electrode layer 350 is arranged on a second region B of thesecond electrode layer 320 such that a portion thereof overlaps with thelight emitting structure 330. A top side of the portion of the firstelectrode layer 350 overlapping with the light emitting structure 330 isin contact with the first conduction type semiconductor layer 336. Inthis instance, the top side of the first electrode layer 350 in contactwith the first conduction type semiconductor layer 336 can positionhigher than the active layer 334.

The first electrode layer 350 includes a contact portion 352 and anexposed portion 354. The contact portion 352 can be a portion in contactwith the first conduction type semiconductor layer 336 passed throughthe second conduction type semiconductor layer 332 and the active layer334 adjacent to one side of the light emitting structure 330 andoverlapped with the light emitting structure 330 in a verticaldirection. The exposed portion 354 can be a portion not overlapped withthe light emitting structure 330 in a vertical direction and exposedfrom the light emitting structure 330.

The top side of the contact portion 352 has a roughness 375 in contactwith the first conduction type semiconductor layer 336. In thisinstance, the roughness 375 can have a regular or an irregular pattern.The roughness 375 can have a shape identical to the roughness 118 inFIG. 1 or the roughness 119 in FIG. 3.

The insulating layer 340 is arranged between the first electrode layer350 and the second electrode layer 320 for electric insulation of thefirst electrode layer 350 from the second electrode layer 320. Theinsulating layer 340 is arranged between a side of the contact portion352 and a passed through portion of the second conduction typesemiconductor layer 332 and between a side of the contact portion 352and a passed through portion of the active layer 334 for insulating thecontact portion 352 from the second conduction type semiconductor layer332 and the active layer 334. And, the insulating layer 340 is formed tosurround a portion of first electrode layer 350 excluding a top sidethereof, i.e., sides and a bottom of the first electrode layer 350 forelectric insulation of the first electrode layer 350 from other layers320, 332, and 334.

The embodiment shown in FIG. 5 increases a contact area between thecontact portion 352 and the first conduction type semiconductor layer336 owing to the roughness 375, enabling to improve the operationvoltage and reliability of the light emitting device as described withreference to FIG. 1, in detail.

Moreover, as the first electrode layer 350 is arranged not on the firstconduction type semiconductor layer 336, but below one side of the firstconduction type semiconductor layer 336, the embodiment shown in FIG. 5does not interfere with a photon traveling in a vertical direction,thereby enabling to improve light emission efficiency of the lightemitting device 300.

There is a contact electrode 371 arranged on the exposed portion 354 ofthe first electrode layer 350, one side the first conduction typesemiconductor layer 336 adjacent to the exposed portion 354, and theconductive layer 360. The contact electrode 371 can have one sideportion in direct contact with the exposed portion 354 of the firstelectrode layer 350, and the other side portion in direct or indirectcontact with the first conduction type semiconductor layer 336 or/andthe conductive layer 360. The first electrode layer 350 can be incontact with the contact electrode 371 or the conductive layer 360 formaking smooth distribution and supply of a current to the firstconduction type semiconductor layer 336.

FIG. 6 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention. Partsidentical to the embodiment described with reference to FIG. 5 will haveidentical reference numerals and description of duplicated portion willbe omitted.

Referring to FIGS. 5 and 6, the light emitting device 400 includes afirst electrode pad 380 arranged on the first electrode layer 350,additionally. For an example, the first electrode pad 380 can bearranged on the exposed portion 354 of the first electrode layer 350.

Though the light emitting device 400 shown in FIG. 6 has the contactelectrode 371 omitted therefrom, the contact electrode 371 may not beomitted in other embodiment.

The first electrode pad 380 can have a size, a position, and a shapevaried with an area of the first electrode layer 350. The firstelectrode pad 380 can be formed of a material identical to the firstelectrode layer 350 or can have gold Au for bonding, additionally.

FIG. 7 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention. Partsidentical to the embodiment described with reference to FIG. 5 will haveidentical reference numerals, and description of duplicated portion willbe omitted.

Referring to FIG. 7, the semiconductor light emitting device 500 has astructure in which a channel layer 145 is added to the structure in FIG.6. The channel layer 145 is arranged on an edge region of the secondelectrode layer 320. The channel layer 145 has a portion arrangedbetween the second electrode layer 320 and the second conduction typesemiconductor layer 332 vertically overlapped with the light emittingstructure 330 and the other portion not overlapped with the lightemitting structure 330.

The channel layer 145 can be a continuous pattern of a band, a ring, aframe or a loop with a predetermined width (For an example, below 2 μm),constructed of single or multiple layers of identical or differentmaterials.

The channel layer 145 can be formed of a light transmissive materialselected from oxides or nitrides or insulating layer materials. For anexample, the channel layer 145 can be selected from ITO (indium tinoxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tinoxide), GZO (gallium zinc oxide), SiO2, SiOx, SiOxNy, Si3N4, Al2O3,TiO2.

The channel layer 145 can be formed of a material identical or differentfrom the insulating layer 340. In this instance, if the channel layer145 is formed of a material identical to the insulating layer 340, thechannel layer 145 can be formed at the same step with the insulatinglayer 340.

The channel layer 145 can prevent interlayer short circuit at a sidewall of the light emitting structure 330 from taking place. The channellayer 145 can prevent moisture from infiltrating into the side wall ofthe light emitting structure 330 and can improve electric reliability ofthe side wall of the light emitting structure 330. And, as a criticalangle of the light incident on the channel layer 145 changes, theoptical extraction efficiency of the light emitting device can beimproved.

There is a passivation layer 390 arranged on a side of the lightemitting structure 330 for electric protection. For an example, thepassivation layer 390 can be arranged to surround sides of the secondconduction type semiconductor layer 332, the active layer 334, and thefirst conduction type semiconductor layer 336. Though the passivationlayer 390 can be formed of an insulating material, such as SiO2, SiOx,SiOxNy, Si3N4, Al2O3, the material is not limited to above.

FIG. 8 illustrates a section of a light emitting device 600 inaccordance with another preferred embodiment of the present invention,and FIG. 9 illustrates a plan view of the light emitting device 600 inFIG. 8. Parts identical to the embodiment described with reference toFIG. 5 will have identical reference numerals, and description ofduplicated portions will be omitted.

Referring to FIG. 8, the light emitting device 600 includes a supportsubstrate 310, a second electrode layer 320, a light emitting structure330, insulating layers 340 and 340-1, a conductive layer 360, and aninternal contact electrode 610.

The first electrode layer 350 has the internal contact electrode 610.For an example, the internal contact electrode 610 can be a horizontalbranch from the first electrode layer 350 to position in the lightemitting structure 330, and have a top side in contact with the firstconduction type semiconductor layer 336. The internal contact electrode610 in the light emitting structure 330 can have a shape not limited toabove, but can have different shapes.

The top side of the internal contact electrode 610 has a roughness375-1. In this instance, the roughness 375-1 can have a regular or anirregular pattern. The roughness 375-1 can be identical to the roughness118 in FIG. 1 or the roughness 119 in FIG. 3.

Accordingly, the roughness 375-1 increases a contact area between theinternal contact electrode 610 and the first conduction typesemiconductor layer 336, enabling to improve the operation voltage andreliability of the light emitting device 600 as described with referenceto FIG. 1.

The insulating layer 340-1 insulates the internal contact electrode 610from other layers 320, 332, and 334. For an example, the insulatinglayer 340-1 can be arranged to surround sides and a bottom of theinternal contact electrode 610 excluding a top side of the internalcontact electrode 610.

The first electrode layer 350 and the internal contact electrode 610 areconnected to each other, and the internal contact electrode 610 can havea ring shape, a loop shape, a frame shape when seen from above. Thoughthe internal contact electrode 610 can have a closed loop shape as shownin FIG. 9, or an open loop in another embodiment. The first electrodelayer 350 and the internal contact electrode 610 can supply a uniformcurrent to an outside circumference of the first conduction typesemiconductor layer 336, thereby improving current supply efficiency.

And, since an edge region of the first conduction type semiconductorlayer 336 is arranged on the insulating layer 340-1 and the internalcontact electrode 610, the insulating layer 340-1 and the internalcontact electrode 610 are not exposed to an outside when seen from a topside of a chip. Therefore, since the internal contact electrode 610 ofthe first electrode layer 350 is not exposed from the top side of thechip, permitting to maintain an upper side size of the first conductiontype semiconductor layer 336, reduction of the light extraction regioncan be prevented.

FIG. 10 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention, and FIG. 11illustrates a plan view of the light emitting device in FIG. 10.Referring to FIGS. 10 and 11, the light emitting device 700 includes asupport substrate 310, a second electrode layer 320, a light emittingstructure 330, a first electrode layer 710, and an insulating layer 730.

The second electrode layer 320 is arranged on the support substrate 310,and the light emitting structure 330 is arranged on the second electrodelayer 320. The first electrode layer 710 has a structure in which thefirst electrode layer 710 is arranged in the light emitting structure330 at a chip center region. The first electrode layer 710 can bearranged at the chip center region on the second electrode layer 320,and the light emitting structure 330 can have a structure in which thelight emitting structure 330 surrounds sides and a top side of the firstelectrode layer 710. In this instance, the light emitting structure 330can expose a portion of the top side of the first electrode layer 710,and the exposed top side of the first electrode layer 710 can bepositioned higher than a top side of the active layer 334 and lower thana top side of the first conduction type semiconductor layer 336.

For an example, the first electrode layer 710 can be in contact with thefirst conduction type semiconductor layer 336 passed through the secondconduction type semiconductor layer 332, and the active layer 334 at thecenter region of the light emitting structure 330. And, a center regionof the first conduction type semiconductor layer 336 can have an opening740 which exposes a portion of the top side of the first electrode layer710. The opening 740 can be a region for making electric patterncontact, or wire bonding.

The first electrode layer 710 can include a contact portion 712 incontact with the first conduction type semiconductor layer 336 passedthrough the second conduction type semiconductor layer 332 and theactive layer 334, and an exposed portion 714 exposed from the firstconduction type semiconductor layer 336 by the opening 740. In thisinstance, the exposed portion 714 can be a center portion of the firstelectrode layer 710, and the contact portion 712 can be an outer portionof the first electrode layer 710.

The top side of the contact portion 712 in contact with the firstconduction type semiconductor layer 336 can have a roughness 720. Theroughness 720 can have a regular pattern or an irregular pattern. Theroughness 720 can be identical to the roughness 118 in FIG. 2 or theroughness 119 in FIG. 3.

The insulating layer 730 is arranged around the first electrode layer710 for insulating the first electrode layer 710 from other layers 320,332, and 336. For an example, the insulating layer 730 can be arrangedto surround sides and a bottom of the first electrode layer 710excluding the top side thereof.

The insulating layer 730 on an underside of the first electrode layer710 can have extensions to an interface between the second conductiontype semiconductor layer 332 and the second electrode layer 320 adjacentto the first electrode layer 710. Since the partial extensions of theinsulating layer 730 can prevent a current flowing from the secondelectrode layer 320 to the first electrode layer 710 from concentratingon a particular region of the light emitting structure 330, the partialextensions can serve as a current blocking layer. Since the firstelectrode layer 710 can supply a current from the center region of thefirst conduction type semiconductor layer 336, spreading of the currentto an entire region of the light emitting structure 330 can be easy.

FIG. 12 illustrates a plan view of a light emitting device 800 inaccordance with another preferred embodiment of the present invention.Parts identical to the parts in the embodiment shown in FIG. 11 will begiven identical reference numerals, and description of duplicatedportions thereof will be omitted.

Referring to FIG. 12, the light emitting structure 800 can have aplurality of cell regions (for an example, two or more than two) whichare divisions of the light emitting device 330. FIG. 12 illustrates aplan view showing the four cell regions A1, A2, A3, and A4 arranged onthe second electrode layer 320 spaced from one another by predetermineddistances.

The embodiment shown in FIG. 12 can be identical to a structure of thelight emitting structure 700 shown in FIG. 11 except that the lightemitting structure 330 has four cell regions spaced from one another bypredetermined distances.

The first electrode layer 710 is arranged in the light emittingstructure 330 at a chip center region, and the first conduction typesemiconductor layer 336 of each of the plurality of the cell regions A1,A2, A3, and A4 has an opening 740 which exposes a portion of the firstelectrode layer 710. For an example, the opening 740 can be positionedat a first corner of each of the cell regions A1, A2, A3, and A4. Inthis instance, the first corner can be a corner positioned at the chipcenter region.

That is, the first electrode layer 710 includes a contact portion incontact with the first conduction type semiconductor layer 336 passedthrough the second conduction type semiconductor layer 332 and theactive layer 334 of each of the plurality of cell regions A1, A2, A3,and A4 arranged at the center region of the light emitting structure330, and an exposed portion exposed from the first conduction typesemiconductor layer 336 by the opening 740.

The contact portion at a top side of the first electrode layer 710 incontact with the first conduction type semiconductor layer 336 has aroughness (not shown). In this instance, the roughness can be identicalto the roughness 118 in FIG. 1 or the roughness 119 in FIG. 3.

There can be an insulating layer (not shown) arranged between theplurality of the cell regions A1, A2, A3, and A4, for insulating a spacebetween each of adjacent cell regions A1, A2, A3, and A4. In thisinstance, a contact electrode connected to the first electrode layer 710is arranged on the insulating layer on each of adjacent cell regions A1,A2, A3, and A4 for efficient supply of power.

FIGS. 13˜17 illustrate sections showing the steps of a method forfabricating a light emitting device in accordance with a preferredembodiment of the present invention. Referring to FIG. 13, a lightemitting structure 130-1 is grown on a growth substrate 810. The growthsubstrate 810 can be formed of at least one selected from sapphireAl2O3, SiC, GaAs, GaN, ZnO, Si, GaP, InP, Ge, but the present inventiondoes not limit above materials. A buffer layer (not shown) or/and anundoped nitride layer (not shown) can also be formed between the lightemitting structure 130-1 and the growth substrate 810 for moderating alattice constant.

The light emitting structure 130-1 can be formed by growing a firstconduction type semiconductor layer 136, an active layer 134, and asecond conduction type semiconductor layer 132 on the growth substrate810 in succession. The light emitting structure 130-1 can be formed by,for an example, MOCVD; Metal Organic Chemical Vapor Deposition, CVD;Chemical Vapor Deposition), PECVD; Plasma-Enhanced Chemical VaporDeposition, MBE; Molecular Beam Epitaxy, HVPE; Hydride Vapor PhaseEpitaxy and the like, but the present invention does not limit to this.

And, a second electrode layer 120 is formed on the second conductiontype semiconductor layer 132. The second electrode layer 120 can haveone of shapes of ohmic layer/reflective layer/bonding layer, ohmiclayer/reflective layer, or reflective layer/bonding layer, but the shapeis not limited to this. For an example, the ohmic layer 124 can beformed on the second conduction type semiconductor layer 132, and thereflective layer 122 can be formed on the ohmic layer 124.

The ohmic layer 124 and the reflective layer 122 can be formed by, foran example, one of E-beam deposition, Sputtering, and PECVD PlasmaEnhanced Chemical Vapor Deposition. An area of each of the ohmic layer124 and the reflective layer 122 can be selected variously.

Next, referring to FIG. 14, at least one recess or hole 412 and 414 isformed to pass through the second electrode layer 120, the secondconduction type semiconductor layer 132, and the active layer 134 toexpose the first conduction type semiconductor layer 136. In thisinstance, the at least one recess or hole 412 and 414 has a bottom witha regular or an irregular roughness 820.

For an example, by using photolithography and etching, the secondelectrode layer 120 is etched selectively to expose a portion of thesecond conduction type semiconductor layer 132, and an exposed secondconduction type semiconductor layer 132 and the active layer 134 underthe active layer 134 are etched to form the at least one recess or hole412 and 414 which exposes the first conduction type semiconductor layer136.

Then, the first conduction type semiconductor layer 136 exposed by therecess or hole 412 and 414 can be subjected to dry etching or PEC PhotoElectro Chemical etching to form a regular or an irregular roughness 820at a bottom of the recess or hole 412 and 414.

Next, referring to FIG. 15, an insulating layer 140 is formed on thesecond electrode layer 120 and sides of the at least one recess or hole412 and 414. In this instance, the insulating layer 140 is not formed atthe bottom of the recess or hole 412 and 414 having the roughness 820.And, the insulating layer 140 can be formed on an edge region of thesecond conduction type semiconductor layer 132 to surround the sides ofthe second electrode layer 120.

Next, referring to FIG. 16, a first electrode layer 115 is formed on theinsulating layer 140 to fill the at least one recess or hole 412 and 414with a conductive material to be in contact with the first conductiontype semiconductor layer 136 exposed thus. In this instance, theconductive material is filled in recess portions of the roughness 820 inthe recess or hole 412 and 414, too. In this instance, the firstelectrode layer 115 filled in the recess or hole 412 and 414 becomes acontact electrode 115-2, and the first electrode layer 115 on theinsulating layer 140 on the second electrode layer 120 becomes a lowerelectrode layer 115-1.

Then, a support substrate 110 is formed on the first electrode layer115. In this instance, the support substrate 110 can be formed bybonding, plating, or deposition.

Next, referring to FIG. 17, the growth substrate 810 is removed from thelight emitting structure 130-1 by using Laser Lift Off or Chemical LiftOff. FIG. 17 illustrates the structure in FIG. 16 in an upside downposition.

And, along unit chip regions, the light emitting structure 130-1 issubjected to isolation etching to separate a plurality of light emittingstructures. For an example, the isolation etching can be made by dryetching, like ICP (Inductively Coupled Plasma). The isolation etchingopens a portion of the second electrode layer 120 from the lightemitting structure 130. For an example, the isolation etching can open aportion of an edge of the second electrode layer 120 as the lightemitting structure 130 is etched by the isolation etching.

Then, a passivation layer 170 is formed to cover sides of the lightemitting structure 130. Though the passivation layer 170 can be formedto cover the sides of the light emitting structure 130 which fall atleast under the second conduction type semiconductor layer 132 and theactive layer 134, but not limited to this, and the passivation layer 170can be formed to cover the sides and a top side of the light emittingstructure 130. Then, a roughness 160 is formed on the top side of thefirst conduction type semiconductor layer 136. And, a second electrodepad 190 is formed on the second electrode layer 120 opened thus.

FIGS. 18 and 19 illustrate sections showing the steps of a method forfabricating a light emitting device in accordance with another preferredembodiment of the present invention.

At first, the steps illustrated in FIGS. 13 and 16 are carried out.However, in FIG. 15, the insulating layer 140 does not cover all thesecond conduction type semiconductor layer 132 adjacent to the one sideof the second electrode layer 120, but is formed to expose one side edgeregion of the second electrode layer 120.

According to this, as shown in FIG. 18, an open region P2 of the firstelectrode layer 115 on the other side of the light emitting structure130 has a height the same with the second electrode layer 120. However,the embodiment is not limited to this, but the open region P2 of thefirst electrode layer 115 can be embodied in a various shapes.

Referring to FIG. 18, after removing the growth substrate 810 from thelight emitting structure 130, the isolation etching is performed, toopen a portion of the second electrode layer 120 and a portion of thefirst electrode layer 115. For an example, the isolation etching canopen a portion P1 of the second electrode layer 120 on one side of thelight emitting structure 130, and the region P2 of the first electrodelayer 115 on the other side of the light emitting structure 130. Then, apassivation layer 170 is formed which covers the sides of the lightemitting structure 130.

Next, referring to FIG. 19, a first electrode pad 210 is formed on oneregion P2 of the first electrode layer 115 opened thus, and a secondelectrode pad 190 is formed on one region P1 of the second electrodelayer 120 opened thus, for an example, on one region P1 of the ohmiclayer 124 or the reflective layer 122 opened thus. The open regions P1and P2 can be singular or plural, and a plurality of the first electrodepads 210 and/or the second electrode pads 190 can be formed. And, aroughness pattern 160 is formed on a top side of the first conductiontype semiconductor layer 136.

FIGS. 20 and 25 illustrate sections showing the steps of a method forfabricating a light emitting device in accordance with another preferredembodiment of the present invention.

Referring to FIG. 20, a light emitting structure 330 is formed on agrowth substrate 910 of a compound semiconductor of group 2˜6 elements.For an example, a first conduction type semiconductor layer 336, anactive layer 334, and a second conduction type semiconductor layer 332are formed on the growth substrate 910. In this instance, the firstconduction type semiconductor layer 336, the active layer 334, and thesecond conduction type semiconductor layer 332 can be identical to thefirst conduction type semiconductor layer 136, the active layer 134, andthe second conduction type semiconductor layer 132 described in FIG. 1.

A roughness (not shown) can be formed on the growth substrate 910. And,a layer or a pattern of a compound semiconductor of group 2˜6 elements,for an example, at least one of a ZnO layer (not shown), a buffer layer(not shown), and an undoped semiconductor layer (not shown) can beformed between the growth substrate 910 and the light emitting structure330. The buffer layer or the undoped semiconductor layer can be formedof a compound semiconductor of group 3˜5 elements, and the undopedsemiconductor layer can be formed of an undoped GaN group semiconductor.

Next, photolithography is performed to form a mask (not shown) on thelight emitting structure 330, and a portion of the light emittingstructure 330 is etched by using the mask as an etching mask, to form anopened portion 915 which exposes a portion of the first conduction typesemiconductor layer 336. For an example, by etching a portion of each ofthe second conduction type semiconductor layer 332, the active layer334, and the first conduction type semiconductor layer 336, the openedportion 915 can be formed, which exposes a portion of the firstconduction type semiconductor layer 336. In this instance, the exposedportion of the first conduction type semiconductor layer 336 can beformed lower than the active layer 334. And, though the opened portion915 can be formed at one side edge region of a unit chip, the positionis not limited to this.

Then, the exposed portion 918 of the first conduction type semiconductorlayer 336 is subjected to dry or PEC etching, to form a roughness 920.In this instance, the roughness 920 can be formed spaced from apredetermined distance from a side 919 of the light emitting structure330 etched thus.

Next, referring to FIG. 22, a first electrode layer 350 is formed at theexposed portion of the first conduction type semiconductor layer 336having the roughness 920 formed therein. In this instance, a portion ofthe first electrode layer 350 can be formed on the roughness 920, andthe first electrode layer 350 can be formed to have a predetermined gap930 between the first electrode layer 350 and the side 919 (See FIG. 21)spaced from the side 919 of the light emitting structure 330 etch thus.

For an example, in order to fill a recessed portion of the roughness920, a conductive material, for an example, at least one of materialselected from Ti, Al, Al alloy, In, Ta, Pd, Co, Ni, Si, Ge, Ag, Agalloy, Au, Hf, Pt, Ru and Au or an alloy thereof can be deposited on theexposed portion 918 of the first conduction type semiconductor layer336, and subjected to patterning by photolithography or etching, to formthe first electrode layer 350 having the gap 930 to the side 919 of thelight emitting structure 330. In this instance, a portion the conductivematerial is filled in the recess portion of the roughness 920 becomesthe roughness 375 of the first electrode layer 350 shown in FIG. 5.

Next, referring to FIG. 23, an insulating layer 340 is formed tosurround a circumference of the first electrode layer 350. For anexample, the insulating layer 340 can be formed on sides and a top sideof the first electrode layer 350, and the insulating layer 340 on thetop side of the first electrode layer 350 can be extended up to aportion of an adjacent top side of the second conduction typesemiconductor layer 332. And, the insulating layer 340 can fill the gap930 between the side 919 of the light emitting structure 330 and thefirst electrode layer 350.

Next, referring to FIG. 24, a second electrode layer 320 is formed onthe second conduction type semiconductor layer 332 and the insulatinglayer 340, and a support substrate 310 is formed on the second electrodelayer 320. The second electrode layer 320 can include at least one of anohmic layer, a reflective layer, and a bonding layer.

Next, referring to FIG. 25, the growth substrate 910 is removed from thelight emitting structure 330 physically or/and chemically. FIG. 25illustrates the structure in an upside down position.

Then, after removing the growth substrate 910, the light emittingstructure 330 exposed thus is subjected to isolation etching. Theisolation etching etches the light emitting structure which falls onboundary regions of unit chips. As the isolation etching etches thelight emitting structure 330, a portion of a top side of the secondelectrode layer 320 is exposed. And, as the isolation etching etches aportion of the first conduction type semiconductor layer 336, though atop side of the first electrode layer 350 is exposed, the roughness 920at the top side of the first electrode layer 350 is not exposed. Thatis, though the isolation etching makes a portion of the top side of thefirst electrode layer 350 having the roughness 920 formed thereon to bein contact with the first conduction type semiconductor layer 336, restof the top side of the first electrode layer 350 can be opened from thefirst conduction type semiconductor layer 336. And, a roughness pattern(not shown) can be formed on the top side of the first conduction typesemiconductor layer 336 for optical extraction efficiency.

Though not shown in FIG. 25, the conductive layer 360 shown in FIG. 6can be formed on the first conduction type semiconductor layer 336, anda contact electrode 371 can be formed, which has one side in contactwith the opened portion of the first electrode layer 350, and the otherportion in direct or indirect contact with the first conduction typesemiconductor layer 336 or/and the conductive layer 360.

FIG. 26 illustrates a section of a light emitting device 900 inaccordance with another preferred embodiment of the present invention.Parts identical to the parts in the embodiment shown in FIG. 5 will begiven identical reference numerals, and description of duplicatedportions thereof will be omitted.

Referring to FIG. 26, the light emitting device 900 includes aninsulating substrate 601, a second electrode layer 320, a light emittingstructure 330, an insulating layer 340, a first electrode layer 350, abottom electrode 610, and a side electrode 620.

Referring to FIG. 26, the embodiment has the insulating substrate 601 asa support substrate, a side electrode 620 arranged at one side of theinsulating substrate 601 connected to one side of the second electrodelayer 320, and the bottom electrode 610 on an underside of theinsulating substrate 601 connected to the side electrode 620. The secondelectrode layer 320 can be connected to the bottom electrode 610 throughthe side electrode 620. Though FIG. 26 illustrates the side electrode620 arranged only one side of the second electrode layer 320, thearrangement is not limited to this, but the side electrode 620 can bearranged at both sides of the insulating substrate 601.

FIG. 27 illustrates a section of a light emitting device 1000 inaccordance with another preferred embodiment of the present invention.Parts identical to the parts in the embodiment shown in FIG. 26 will begiven identical reference numerals, and description of duplicatedportions thereof will be omitted.

Referring to FIG. 27, the light emitting device 1000 includes aninsulating substrate 601, a second electrode layer 320, a light emittingstructure 330, an insulating layer 340, a first electrode layer 350, abottom electrode 610, and a pass through electrode 630.

Referring to FIG. 27, the embodiment includes at least one pass throughelectrode 630 in a shape of via connected between the second electrodelayer 320 and the bottom electrode 610 passed through the insulatingsubstrate 601. In this instance, the pass through electrode 630 can haveone end in contact with the bottom electrode 610, and the other end incontact with the second conduction type semiconductor layer 332 passedthrough the second electrode layer 320. And, in another embodiment, thepass through electrode 630 can have the other end only in contact with abottom side of the second electrode layer 320 passed through theinsulating substrate 601.

The light emitting device in any one of the foregoing embodiments has anincreased adhesion between the first electrode layer 350 and the firstconduction type semiconductor layer 336, thereby improving reliability.

FIG. 28 illustrates a section of a light emitting device 100-1 inaccordance with another preferred embodiment of the present invention.Parts identical to the parts in the embodiment shown in FIG. 1 will begiven identical reference numerals, and description of duplicatedportions thereof will be omitted.

Referring to FIG. 28, the light emitting device 100-1 includes a supportsubstrate 110, a first electrode layer 115, a second electrode layer120, a light emitting structure 130, an insulating layer 140, aprotective layer 170, and a second electrode pad 190.

The top side of the contact portion 115-2 in contact with the firstconduction type semiconductor layer 136 has a roughness, for an example,a first roughness 118-1. A portion 141 (See FIG. 1) of the insulatinglayer 140 surrounding the contact electrode 115-2 is in contact with thefirst conduction type semiconductor layer 136, and a portion of theinsulating layer 140 in contact with the first conduction typesemiconductor layer 136 has a second roughness 118-2. For an example, ona top side of a portion of the insulating layer 140 surrounding the sideof the contact electrode 115-2 can have the second roughness 118-2. Thefirst roughness 118-1 and the second roughness 118-2 can have a randomirregular shape.

The first roughness 118-1 formed on the top side of the contact portion115-2 and the second roughness 118-2 formed on the top side of a portionof the insulating layer 140 increases a contact area between the firstconduction type semiconductor layer 136 and the insulating layer 140 toimprove reliability of the light emitting structure 100-1.

FIG. 29 illustrates a section of a light emitting device in accordancewith another preferred embodiment of the present invention. The lightemitting device 100-2 includes a support substrate 505, a secondelectrode layer 510, an insulating layer 520, a first electrode layer530, a light emitting structure 540, a protective layer 555, and a firstelectrode pad 560.

The light emitting structure 540 includes a second conduction typesemiconductor layer 542, an active layer 544, and a first conductiontype semiconductor layer 546. The first electrode layer 530 is arrangedunder the light emitting structure 540. For an example, the firstelectrode layer 530 can be arranged under the second conduction typesemiconductor layer 542. The light emitting structure 540 can beidentical to the light emitting structure described with reference toFIG. 1.

The first electrode layer 530 is in contact with the first conductiontype semiconductor layer 546 passed through the second conduction typesemiconductor layer 542 and the active layer 544. The first electrodelayer 530 has a roughness 532 at a portion in contact with the firstconduction type semiconductor layer 546. In this instance, the roughness532 can be identical to one described with reference to FIG. 1.

For an example, the first electrode layer 530 includes a first lowerelectrode layer 534 and at least one first contact electrode 536. Thefirst lower electrode layer 534 can be arranged between the lightemitting structure 540 and the second electrode layer 510. The at leastone first contact electrode 536 is a branch from the first lowerelectrode layer 534 in contact with the first conduction typesemiconductor layer 546 passed through the second conduction typesemiconductor layer 542 and the active layer 544.

The second electrode layer 510 is arranged on the support substrate 505.The second electrode layer 510 is arranged on an underside the firstelectrode layer 530. The second electrode layer 510 is in contact withthe second conduction type semiconductor layer 942 passed through thefirst electrode layer 930. The second electrode layer 510 can have aroughness 512 at a portion in contact with the second conduction typesemiconductor layer 542.

For an example, the second electrode layer 510 can include a secondlower electrode 514 arranged under the first electrode layer 530, and asecond lower electrode layer 516 which is a branch from the second lowerelectrode 514 in contact with the second conduction type semiconductorlayer 542 passed through the first electrode layer 530.

The second electrode layer 510 can include at least one of a bondinglayer, a barrier layer, a reflective layer, and an ohmic layer.

The insulating layer 520 can be arranged between the first electrodelayer 530 and the second electrode layer 510, between the secondconduction type semiconductor layer 542 and the first electrode layer530, and between the active layer 544 and the first electrode layer 530.The protective layer 555 is arranged at a side of the light emittingstructure 540.

For an example, the insulating layer 520 can be arranged between thesecond lower electrode 514 and first lower electrode layer 534, betweenthe first contact electrode 516 and the first lower electrode layer 534,between the second conduction type semiconductor layer 542 and the firstlower electrode layer 534, between the second conduction typesemiconductor layer 542 and the first contact electrode 536, and betweenthe active layer 544 and the first contact electrode 536. And, theinsulating layer 520 can be arranged between a side of the first contactelectrode 536 and the first conduction type semiconductor layer 546.

The first electrode layer 530 has one side region exposed from the lightemitting structure 540, and the first electrode pad 560 is arranged onone region of the first electrode layer 530 exposed from the lightemitting structure 130.

Since the first contact electrode 536 has the roughness 532 at the topside, the first contact electrode 536 has an increased contact area tothe first conduction type semiconductor layer 546. And, as the contactarea between the first contact electrode 536 and the first conductiontype semiconductor layer 546 increases, resistance of the firstelectrode layer 530 is reduced, to drop an operation voltage of thelight emitting device 100-2, thereby enabling to improve optical outputefficiency. And, as the contact area between the first contact electrode536 and the first conduction type semiconductor layer 546 increases,adhesion between the first electrode layer 530 and the first conductiontype semiconductor layer 546 increases, to improve reliability of thelight emitting device 100-2.

Moreover, the roughness 512 at the top side of the second contactelectrode 536 increases adhesion between the second electrode layer 510and the second conduction type semiconductor layer 542, enabling toimprove reliability of the light emitting device 100-2.

FIG. 30 illustrates a section of a light emitting device package inaccordance with a preferred embodiment of the present invention.Referring to FIG. 30, the light emitting device package 1100 includes apackage body 1710, a first metal layer 1712, a second metal layer 1714,a light emitting device 1720, a reflective plate 1725, a wire 1730, anda resin layer 1740.

The package body 1710 has a cavity at one side region. In this instance,a side wall of the cavity can be sloped. The package body 1710 can beconstructed of a substrate having good insulating property and thermalconductivity, such as a silicon based wafer level package, a siliconsubstrate, silicon carbide SiC, and aluminum nitride AlN, and have astructure in which a plurality of substrates are stacked. The embodimentdoes not limit a material, a structure and a shape of the body describedabove.

The first metal layer 1712 and the second metal layer 1714 are arrangedon a surface of the package body 1710 so as to be separated electricallyfrom the light emitting device 1720 taking heat dissipation and mountingof the light emitting device 1720 into account. The light emittingdevice 1720 is connected to the first metal layer 1712 and the secondmetal layer 1714, electrically. The light emitting device 1720 can beany one of the light emitting devices 100˜1000, 100-1 described inforegoing embodiments.

For an example, the support substrate 110 of the light emitting device100 in FIG. 1 can be connected to the second metal layer 1714electrically, the second electrode pad 190 can be bonded to one side ofthe wire 1730, and the other side of the wire 1730 can be bonded to thefirst metal layer 1712.

And, for an example, the support substrate 110 of the light emittingdevice 200 in FIG. 2 can be arranged on the second metal layer 1714 orthe package body 1710, and the first electrode pad 210 can be connectedto the second metal layer 1714, electrically. For an example, the firstelectrode pad 210 can be wire bonded to the second metal layer 1714. Thesecond electrode pad 190 can be bonded to one side of the wire 1730, andthe other side of the wire 1730 can be bonded to the first metal layer1712.

And, for an example, the support substrate 310 of the light emittingdevice 300 or 700 in FIG. 5 or 10 can be connected to the second metallayer 1714 electrically, and the first electrode 350 or 1710 can bebonded to one side of the wire 1730, and the other side of the wire 1730can be bonded to the first metal layer 1712.

The reflective plate 1725 can be formed on the side wall of the cavityof the package body 1710 such that a light from the light emittingdevice is directed toward a predetermined direction. The reflectiveplate 1725 is formed of a light reflective material, for an example, canbe a metal coating, or a metal foil.

The resin layer 1740 surrounds the light emitting device 1720 positionedin the cavity for protecting the light emitting device 1720 from anexternal environment. The resin layer 1740 can be formed of a colorlesstransparent polymer resin material, such as epoxy or silicone. The resinlayer 1740 can contain a fluorescent material for changing a wave lengthof the light from the light emitting device 1720.

Since light emitting device package of the embodiment includes a lightemitting device of which reliability is improved, reliability of thelight emitting device package can be improved.

An array of the light emitting device packages can be on a substrate,and a light guide plate, a prism sheet, a diffusion sheet, and the likethat are optical members can be arranged on a light path of the lightemitting device package.

As another embodiment, a display device, an indicating device, or alighting system can be produced, which includes the semiconductor lightemitting device or the light emitting device package described in theforegoing embodiments, and the lighting system can include a lamp, astreet light, and a car lighting device.

FIG. 31 illustrates an exploded perspective view of a lighting device1200 having a light emitting device in accordance with another preferredembodiment of the present invention applied thereto. Referring to FIG.31, the lighting device 1200 includes a power source coupler 1110, aheat sink 1120, a light emitting module 1130, a reflector 1140, a covercap 1150, and a lens unit 1160.

The power source coupler 1110 has a top side with a screw for placing inan external power source socket (not shown) to supply power to the lightemitting module 1130. The heat sink 1120 dissipates heat from the lightemitting module 1130 through heat dissipating fins at a side thereof.The heat sink 1120 has a top side screw coupled to a bottom side of thepower source coupler 1110.

The heat sink 1120 has a bottom side having the light emitting module1130 which includes the light emitting device packages mounted to acircuit board secured thereto. In this instance, the light emittingdevice packages can be the light emitting device package in accordancewith the embodiment shown in FIG. 30.

The lighting device 1200 can include an insulating sheet 1132 and areflective sheet 1134 under the light emitting module 1130 for electricprotection of the light emitting module, additionally. Moreover, opticalmembers which can perform various optical functions can be arranged on alight travel path of the light from the light emitting module 1130.

The reflector 1140 of a circular truncated cone shape is coupled to anunderside of the heat sink 1120 for reflecting the light from the lightemitting module 1130. The cover cap 1150 of a circular ring shape iscoupled to an underside of the reflector 1140. The lens unit 1160 isplaced in the cover cap 1150. The lighting device 1200 in FIG. 31 can beused as a downlight buried in a ceiling or wall of a building. Since thelighting device includes the light emitting device package of whichreliability is improved, reliability of the lighting device can beimproved.

FIG. 32A illustrates an exploded perspective view of a display unithaving a light emitting device package in accordance with a preferredembodiment of the present invention applied thereto, and FIG. 32Billustrates a section of a light source portion of the display unit inFIG. 32A.

Referring to FIGS. 32A and 32B, the display unit includes a backlightunit and a liquid crystal display panel 860, a top cover 870, and afastening member 850.

The backlight unit includes a bottom cover 810, a light emitting module880 on one side of inside of the bottom cover 810, a reflective plate820 arranged on a front of the bottom cover 810, a light guide plate 830arranged on a front of the reflective plate 820 for guiding the lightfrom the light emitting module 880 toward a front of the display device,and an optical member 840 arranged on a front of the light guide plate830. The liquid crystal display panel 860 is arranged on a front of theoptical member 840, the top cover 870 is provided to a front of theliquid crystal display panel 860, the fastening member 850 is arrangedbetween the bottom cover 810 and the top cover 870 and fastened togetherwith the bottom cover 810 and the top cover 870.

The light guide plate 830 serves to guide the light from the lightemitting module 880 to be emitted as a surface light source, thereflective plate 820 on a rear of the light guide plate 830 causes thelight from the light emitting module 880 to be reflected toward thelight guide plate 830 for improving light efficiency. However, thereflective plate 820 can be provided as a separate element as shown inthe drawing, or provided as a coat of a high reflectivity materialapplied to the rear of the light guide plate 830 or to the front of thebottom cover 810. In this instance, the reflective plate 820 can beformed of a material which has high reflectivity and can be very thin,such as PolyEthylene Terephtalate PET.

And, the light guide plate 830 scatters the light from the lightemitting module 880 for uniform distribution of the light to an entireregion of a screen of the liquid crystal display panel 860. Accordingly,the light guide plate 830 is formed of a material having goodrefractivity and transmissivity, such as PolyMethylMethAcrylate PMMA,PolyCarbonate PC, or PolyEthylene PE.

And, the optical member 840 on the light guide plate 830 causes thelight from the light guide plate 830 to diverge at a predeterminedangle. The optical member 840 causes the light lead by the light guideplate 830 to travel toward the liquid crystal display panel 860,uniformly.

The optical member 840 can be a selective stack of optical sheets, suchas a diffusion sheet, a prism sheet, or a protective sheet or amicro-lens array. In this instance, a plurality of the optical sheetscan be used, and can be formed of acryl resin, polyurethane resin, ortransparent resin, such as silicone resin. And, the prism sheet cancontain a fluorescent sheet.

The liquid crystal display panel 860 can be provided to the front of theoptical member 840. In this instance, it is apparent that, instead ofthe liquid crystal display panel 860, other kinds of display devicewhich requires the light source can be provided to the front of theoptical member 840.

The reflective plate 820 is placed on the bottom cover 810, and thelight guide plate 830 is placed on the reflective plate 820. Accordingto this, the reflective plate 820 can be in contact with the heatdissipating member (not shown) directly. The light emitting module 880includes a light emitting device package 882 and a printed circuit board881. The light emitting device package 882 is mounted on the printedcircuit board 881. The light emitting device package 881 can be theembodiment illustrated in FIG. 30.

The printed circuit board 881 can be bonded to a bracket 812. Thebracket 812 can be formed of a material having high heat conductivityfor heat dissipation in addition to fastening of the light emittingdevice package 882, and though not shown, a heat pad can be providedbetween the bracket 812 and the light emitting device package 882 foreasy heat transfer. And, as shown, the bracket 812 has a └ shape suchthat a transverse portion 812 a is supported on the bottom cover 810 andthe longitudinal portion 812 b is fastened to the printed circuit board881. Since the display unit of the embodiment includes the lightemitting device package of which reliability is improved, reliability ofthe display unit can be improved.

As has been described, the light emitting device of the presentinvention can improve an operation voltage and reliability.

Features, structures, effects, and so on described in above embodimentsare included to at least one of embodiments, but not limited to only oneembodiment invariably. Furthermore, it is apparent that the features,the structures, the effects, and so on described in the embodiments canbe combined, or modified with other embodiments by persons skilled inthis field of art. Therefore, it is required to understand that suchcombination and modification is included to scope of the presentinvention.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A light emitting device comprising: a lightemitting structure including a second conduction type semiconductorlayer, an active layer, and a first conduction type semiconductor layer;a second electrode layer arranged under the light emitting structure; afirst electrode layer having at least one portion extending to contactthe first conduction type semiconductor layer passing the secondconduction type semiconductor layer and the active layer; and aninsulating layer arranged between the second electrode layer and thefirst electrode layer, between the second conduction type semiconductorlayer and the first electrode layer, and between the active layer andthe first electrode layer, wherein the first electrode layer includes: acontact portion passing the second conduction type semiconductor layerand the active layer and contacting the first conduction typesemiconductor layer, wherein the contact portion is overlapped with thelight emitting structure in a vertical direction, and an exposed portionnot overlapped with the light emitting structure in the verticaldirection and exposed at a sidewall of the light emitting structure,wherein a top side of the exposed portion is positioned higher than atop side of the active layer, and the vertical direction is a directionfacing from the second electrode layer toward the first conduction typesemiconductor layer, wherein the top side of the exposed portion isexposed at the sidewall of the light emitting structure, and wherein atop side of the contact portion contacts the first conduction typesemiconductor layer and the top side of the contact portion contacts thetop side of the exposed portion.
 2. The light emitting device as claimedin claim 1, wherein the first electrode layer has an internal contactelectrode and the internal contact electrode is a horizontal branch fromthe first electrode layer to be positioned in the light emittingstructure.
 3. The light emitting device as claimed in claim 1, wherein atop side of the contact portion has a roughness.
 4. The light emittingdevice as claimed in claim 1, wherein the top side of the exposedportion of the first electrode layer is exposed from the insulatinglayer, and wherein the contact portion does not contact the secondconduction type semiconductor layer and the active layer.
 5. The lightemitting device as claimed in claim 1, wherein a top side of the contactportion is flush with the top side of the exposed portion.
 6. A lightemitting device package comprising: a package body; a light emittingdevice on the package body; a first electrode and a second electrodeprovided on the package body connected to the light emitting device; anda resin layer which surrounds the light emitting device, wherein thelight emitting device includes; a light emitting structure including asecond conduction type semiconductor layer, an active layer, and a firstconduction type semiconductor layer; a second electrode layer arrangedunder the light emitting structure; a first electrode layer having atleast one portion extending to contact the first conduction typesemiconductor layer passing the second conduction type semiconductorlayer and the active layer; and an insulating layer arranged between thesecond electrode layer and the first electrode layer, between the secondconduction type semiconductor layer and the first electrode layer, andbetween the active layer and the first electrode layer, wherein thefirst electrode layer includes: a contact portion passing the secondconduction type semiconductor layer and the active layer and contactingthe first conduction type semiconductor layer, wherein the contactportion is overlapped with the light emitting structure in a verticaldirection, and an exposed portion not overlapped with the light emittingstructure in the vertical direction and exposed at a sidewall of thelight emitting structure, wherein a top side of the exposed portion ispositioned higher than a top side of the active layer, and the verticaldirection is a direction facing from the second electrode layer towardthe first conduction type semiconductor layer, wherein the top side ofthe exposed portion is exposed at the sidewall of the light emittingstructure, and wherein a top side of the contact portion contacts thefirst conduction type semiconductor layer and the top side of thecontact portion contacts the top side of the exposed portion.
 7. Thelight emitting device as claimed in claim 6, wherein a top side of thecontact portion has a roughness, and wherein the contact portion doesnot contact the second conduction type semiconductor layer and theactive layer.
 8. A light emitting device comprising: a light emittingstructure including a second conduction type semiconductor layer, anactive layer, and a first conduction type semiconductor layer; a secondelectrode layer arranged under the light emitting structure; a firstelectrode layer having at least one portion extending to contact thefirst conduction type semiconductor layer passing the second conductiontype semiconductor layer and the active layer; and an insulating layerarranged between the second electrode layer and the first electrodelayer, between the second conduction type semiconductor layer and thefirst electrode layer, and between the active layer and the firstelectrode layer, wherein a first portion of the first electrode layerpasses through the second conduction type semiconductor layer and theactive layer, and contacts the first conduction type semiconductor layerand the first portion is overlapped with the light emitting structure ina vertical direction, and wherein a second portion of the firstelectrode layer is not overlapped with the light emitting structure inthe vertical direction and is exposed at a side surface of the lightemitting structure, and wherein a top side of the second portion ispositioned higher than a top side of the active layer, and the verticaldirection is a direction facing from the second electrode layer towardthe first conduction type semiconductor layer, wherein the top side ofthe second portion is exposed at the sidewall of the light emittingstructure, and wherein a top side of the first portion contacts thefirst conduction type semiconductor layer and the top side of the firstportion contacts the top side of the second portion.
 9. The lightemitting device as claimed in claim 8, wherein the first portion has afirst roughness contacting with the first conduction type semiconductorlayer.
 10. The light emitting device as claimed in claim 9, wherein thefirst roughness has a width of 0.02 μm˜100 μm and a height of 0.2 μm˜10μm.
 11. The light emitting device as claimed in claim 8, wherein thefirst electrode layer is arranged on the second electrode layer, andwherein the first portion does not contact the second conduction typesemiconductor layer and the active layer.
 12. The light emitting deviceas claimed in claim 8, wherein the second electrode layer includes atleast one of an ohmic layer, a reflective layer, and a bonding layer.13. The light emitting device as claimed in claim 8, wherein the firstportion has a top side higher than the top side of the active layer andlower than a top side of the first conduction type semiconductor layer.14. The light emitting device as claimed in claim 8, wherein theinsulating layer surrounds sides and a bottom of the first electrodelayer.
 15. The light emitting device as claimed in claim 14, wherein theinsulating layer has extensions to an interface between the secondconduction type semiconductor layer and the second electrode layeradjacent to the first electrode layer.
 16. The light emitting device asclaimed in claim 9, wherein the first electrode layer has an internalcontact electrode and the internal contact electrode is a horizontalbranch from the first electrode layer to position in the light emittingstructure.
 17. The light emitting device as claimed in claim 8, furthercomprising a conductive layer arranged on the first conduction typesemiconductor layer.
 18. The light emitting device as claimed in claim16, wherein the internal contact electrode has a top side in contactwith the first conduction type semiconductor layer and the top side ofthe internal contact electrode has a roughness.
 19. The light emittingdevice as claimed in claim 16, wherein the first electrode layer and theinternal contact electrode are electrically connected to each other. 20.The light emitting device as claimed in claim 8, wherein the top side ofthe second portion of the first electrode layer is exposed from theinsulating layer.